Television receiver with safety plate and mounting means



FIORE ETAL 3,084,217

VER WITH SAFETY PLATE AND MOUNT Filed Aug 18 1960 April 2, 19 3. J- P.

TELEVISION RECEI ING MEANS o 6 so amT/ #44 Mr v 8/ 2 M n m 0 535% I Z. T Lnm m M h 5 w m n ma p Z :70 C r ay hired rates 3,684,217 TELEVISIGN RECEWER WITH SAFETY PLATE AND MUUNTING MEANS doseph P. Flore, Chicago, and Carl J. Steinke, Des Plaines,

lll., assignors to Zenith Radio Corporation, a corporaion of Delaware Filed Aug. 18, 196i), Ser. No. 50,492. 8 Saints. (Cl. 1.78-7.82)

This invention relates in general to television receivers and more particularly to an improved mounting arrangement for the television picture tube and its associated safety plate.

A most important safety device requiredin'television receivers today is the transparent safety plate or Window which is positioned immediately in front of thedisplay panel of the television picture tube for the purpose of protecting the viewer in the event of a tube implosion, While a variety of arrangements for mounting this plate-are utilized, common practice is to employ a support which peripherally anchors or fixes the safety plate. Aswillbe shown, this practice can contribute to safety plate failure should the tube implode.

In order to more fully appreciate the problem presented by a tube implosion, the suspected sequence of events will 'bebriefly related. The implosion is generally initiated by a crack or fault on the external surface of the highly evacuated tube envelope. Since substantial portions of this surface are under tension due to the force exerted by atmospheric pressure, a multitude of additional fissures are instantly developed. As a result there is a more or less complete mechanical break-up of the tube manifested in part by a violent dispersion of glass particles. As a rule the display panel is destroyed by forwardly directed particlesso that the safety plate is scored or scratched. It is, of course, the purpose of this plate to intercept the flying glass and confine the effect of the implosion to the television cabinet proper. However, in addition to this scoring of the plate by the glass particles, there is an additional factor which must be considered, namely, the opposite" sides of the safety plate are now instantaneously subjected to a substantial pressure differential, a very low pressure .on the inside and atmospheric pressure on the outside.

As a result the plate is driven toward the tube under the impetus of atmospheric pressure. safety plate is constrained about its periphery, the plate tends to bow inwardly subjecting the inner surface of the plateto tension forces. At this instant the plate is readily susceptible to failure because of the inability of the scratched inner surface to withstand the tension forces. resently known solutions to such plate failure problems contemplate in general the use of tempered glass or resort is heavier plate, both rather expensive expedients.

In this same area, it is also known to employ a rubber .ring between the safety plate and the display panel. of the as well as its mounting trappings, a laminated picture tube has recently been introduced. This tube comprises a more or less conventional picture tube to the front panel of which a bowl, conforming substantially to this paneland containing a quantity of transparent epoxy resin, is sealed Since the edgeofthe ate'nt consumer be expected, the additional processing required during the manufacture of a laminated tube is reflected in its original cost which is significantly more than that of a conventional picture tube. Moreover, the set owner isplaced at a decided disadvantage, in an economic sense, when it is realized that at such times as a new picture tube is required, no part of the laminated tube is reusable by the Insofar as the viewer is concerned, heis required to duplicate his original investment whenever the picture tube fails.

It is therefore a general object of the invention to provide a television receiver ,characterized by an improved mounting arrangement forthe cathode ray tube and its associated safety-window plate. a

It is a principal object of the invention to provide a mounting arrangement for the safetyplate of a television receiver which readily permits the window to withstand the destructive forces accompanying a cathode-ray tube implosion.

It is a further object ofthe invention to provide a novel mounting arrangement for yieldably suspending the safety window of a television receiver.

"It is also an object of the invention to provide a cathoderay tube-safety window assembly which-effects substan tial economies over prior art arrangements.

A television receiver constructed in accordance with the invention comprises a cathode-ray tube'having a display paneland a memberdisposed in a'parallel relation to provide, in effect, a double-paned window. As would framing member.

to the panel having a configuration which effectively frames the panel. A transparent safety plate having an area at least substantially equate the frame area provided by the aforesaid member is positioned'behind the Pneumatic cushioning means comprising a gasket is interposed between .the display panel and the framing member to accommodate relative movement of the plate and the tube in a direction toward one another when the plate is subjected to adisturbing force.

In a particular embodiment this gasket is'provided with a first portion which defines a channel that receives and engages the plate about its perimeter in order to suspend yieldably the plate in an overlying relation to the display panel and within the defined frame area, Thegasket is further provided with a second portion which confronts the display panel and-is deformable to the peripheral surface thereof and defines, with thefirst portion of the gasket, the cushion section which is yieldable to accommodate relative movement of the plate and the tube. Finally, means are provided for norm-ally fixing the tube, the frame member and the gasket against relative movement.

The features of this invention which are believed to-be novel are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood, however, by reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify like elements, and in which:

FIGURE '1 is a plan view, partly in section, of a television receiver embodying the invention;

FIGURE 2 shows a cross section of the gasket employed for suspending the'safety plate in the television receiver of FIGURE 1;

FIGURE 3 is a fragmentary view, partly in section, illustrating the manner in which the gasketed safety plate of the television receiveris suspended; and

FIGURE 4 is an elevational view, partly in section, of a television receiver comprising an alternate embodi- .ment of the invention.

The television'receiver 10 shown in FIGUREI comprises a chassis 11, a cabinet 12 fastened to the chassis and a cathode-ray picture tube 13 having a display panel 14 bounded by a peripheral portion 15. A framing member 16, which in the preferred embodiment comprises an escutcheon, is disposed in a parallel relation to panel 14 and has aconfiguration determined by. a radially extending lip 17 which effectively frames the viewing area of panel 14. As shown, escutcheon 15 is secured to flanges 35 projecting inwardly from the walls of cabinet 12 by conventional fasteners. Theescutcheon may also be fastened to the chassis if additional rigidity is required. The back wall of the escutcheon is relieved to form a well 18, the purpose of which will be explained shortly. A transparent glass safety plate 19, having an area at least substantially equal to the frame area afforded by escutcheon 16, is positioned behind the escutcheon.

Pneumatic cushioning means comprising a gasket is interposed between display panel 14- and escutcheon 16 for the purpose of suspending safety plate 19 in an overlying relation to panel 14 and within the frame area of the escutcheon.

More particularly, and as best shown in FIGURES 2 and 3, gasket 29 comprises a first portion'21 which defines a channel for receiving and engaging safety plate 19 about of safety plate 19. The gasket includes a second portion 24 which confronts display panel 14 and is conformable to the peripheral surface 15 thereof. Portion 24 in conjunction with portion 21 defines a principal bulbous section 25 that constitutes, in effect, a pneumatic cushion which is yieldable to accommodate relative movement of plate 19 and tube 13 should either be displaced in a direction toward one another. A length 26 of portion 24 which confronts panel 14 is likewise serrated in order to insure positive gripping action as well as to contribute to a substantially air-tight dust seal between safety plate 19 and display panel 14. The extremity Sil'of length 26 which joins channel 21 is cut back sharply so as to refleet light from the televised scene, as well as ambient light, back toward display panel 14. This obviates an otherwise undesirable ring of reflection about the perimeter of the televised scene.

Preferably gasket 26 is additionally provided with a 7 third portion 27 which confronts escutcheon 16 and is conformable to an inner peripheral surface of that member, more particularly, the inside radius of well 18. Portion 27 defines with portion 21 a minor bulbous section efficiency of the gasket is but insignificantly affected by an imperfect end-seal. Means are provided for normally fixing tube 13, escutcheon 16 and gasket 20 against relative movement. More particularly, such means comprise a ring-like harness 29, which engages the funnel section 30 of picture tube 13, and a plurality of straps 31 which are looped around harness 29 and secured to bosses 32 extending rearwardly from escutcheon 16. The extremities of harness 29 are retained by a bolt and nut fastening 33.

Before discussing the manner in which the abovedescribed safety plate mounting arrangement reacts to a tube implosion, the method of assembling those components of the receiver, which are significant insofar as the invention is concerned, will be briefly described. First escutcheon 16 is positioned upon a suitable support with well 18 facing upward. A gasketed safety plate is then placed in the well with minor bulbous or cushion portion 28 seated against the inner radius of the well. Picture tube 13 is then positioned upon the principal cushion portion 25 of the gasket. Thereafter harness 29 is mounted upon the funnel of tube 13 and straps 31 are securely fastened to bosses 32 of the escutcheon. As fastener 33 is taken up, the picture tube is drawn toward the escutcheon so that the bulbous portion 25 of the gasket tends to conform to periphery 15 of the face panel while the minor bulbous portion 28 is partially compressed to provide a yieldable barrier between safety plate 19 and the escutcheon. As will be shown, this suspension arrangement permits safety plate 3.9, in effect, to float between escutcheon 16 and face panel 14 of the tube. Furthermore, only the picture tube requires any type of mounting hardware since the gasketing arrangement for the safety plate renders unnecessary any separate facilities for mounting it in the receiver.

Accordingly, in the event of a tube implosion, safety plate 19 by virtue of its floating type mount is driven bodily toward the tube by the force of atmospheric pressure bearing upon the outside surface of the plate. Instantaneously, pneumatic cushion portion 25 of the gasket yields to accommodate the inital inward displacement of the plate. Then as the plate continues inward the air entrapped within cushion 25 is further compressed to provide a progressively increasing retardation of the safety plate. As a result the kinetic energy imparted to the plate is dissipated and the possibility of safety plate failure is substantially eliminated. It is, of course, possible that the plate will rebound with some force. It is then a purpose of cushion portion 28 to absorb any remaining energy in the plate in the same fashion as cushion 25. Now even if the seal formed at the junction of the gasket extremities is imperfect, the ability of the pneumatic cushion portions to absorb the force of the implosion is but little affected. This obtains because the displacement of the safety plate during an implosion is substantially instantaneous in nature and the amount of air which could escape from an imperfect seal during this time can have but slight effect upon the cushioning.

Additionally, this novel gasketing arrangement affords a substantially air tight seal between the safety plate and the face panel of the tube, thus preventing the accumulation of dust and other foreign matter on the viewing screen of the picture tube. Furthermore, the expense of picture tube replacement is minimized since the safety plate as well as the gasket are, of course, reuseable.

The above-described embodiment contemplates a mounting arrangement for fixing the picture tube 13 and gasket 20 against relative movement by securing the tube to a support whichalso serves as an escutcheon for the receiver. It is equally the purview of the invention to utilize the alternate embodiment of FIGURE 4 in which the support member 40 is employed in place of escutcheon 16. More particularly, member 40' comprises a mask-like clamp having an aperture which effectively frames display panel 14. The inner surface of member 40 conforms in general to the peripheral portion of display panel 14 so as to define an oval concavity 41. Member 40 is also provided with a pair of support legs 42 (only one shown) which are bolted to chassis 11, an upwardly extending flange 43 that is secured to the top wall of cabinet 12 and a plurality of ears 44- to which harness straps 31 are secured. Gasketed safety plate 19 is snugly seated within concavity 41 intermediate clamp 40 and picture tube 13 and retained therein by the same harness arrangement employed in the principal embodiment. A separate escutcheon 45 overlies support member 40 and is secured to the top and bottom walls of cabinet 12. Escutcheon 45 may comprise a molded plastic piece or an inexpensive stamping thus realizing a significant saving in cost. In all other respects the embodiment of FIGURE 4 is substantially identical to the principal embodiment of FIGURE 1 and thus no additional description is deemed necessary.

In summary, the subject invention provides a novel arrangement for securing a television picture tube and its associated safety plate within the receiver cabinet. Specifically, the plate is retained by a gasket having a yieldable cushion portion adjacent the display panel of the tube in order to accommodate movement of the plate in the event the plate is displaced by the forces accompanying a tube implosion.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made therein without departing from the invention in its broader aspects. The aim of the appended claims, therefore, is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

We claim:

-1. A television receiver comprising: a cathode-ray tube having a display panel; a member disposed in a parallel relation to said panel and having a configuration to effectively frame said panel; a transparent safety plate having an area at least substantially equal to the frame area provided by said member; means for yieldably suspending said safety plate in overlying relation to said display panel and within the aforesaid frame area comprising a gasket having a first portion which definesa channel for receiving and engaging said plate about its perimeter, said gasket having a second portion confronting said display panel and conformable to the peripheral' surface thereof and defining with said first portion'a chambered section yieldably accommodating relative movement of said plate and said tube in a direction toward one another when said.

plate is subjected to a disturbing force; and means for normally fixing said tube, said frame member, and said gasket against relative movement.

2. A television receiver comprising: a cathode-ray tube having a display panel; an escutcheon disposed in a parallel relation to said panel and having a configuration to eifectively frame said panel; a transparent safety plate having an area at least substantially equal to the frame area provided by said escutcheon; means for yieldably suspending said safety plate in overlying relation to said display panel and within the aforesaid frame area comprising a gasket having a first portion which defines a channel corresponding substantially to the outline of said safety plate for receiving and engaging said plate about its perimeter, said gasket having a second portion confronting said display panel and conformable to the peripheral surface thereof and defining with said first portion a chambered section yieldably accommodating relative movement of said plate and said tube in a direction toward one another when said plate is subjected to a disturbing force; and tube mounting means cooperating with said escutcheon for normally fixing said tube, and escutcheon, and said gasket against relative movement.

3. A television receiver comprising: a cathode-ray tube having a display panel; a support member disposed in a parallel relation to said panel and having a configuration to effectively frame said panel; a transparent safety plate having an area at least substantially equal to the frame area provided by said support member; means for yieldably suspending said safety plate in overlying relation to said display panel and within the aforesaid frame area comprising a gasket having a first portion which defines a channel corresponding substantially to the outline of said safety plate for receiving and engaging said plate about its perimeter, said gasket having a second portion confronting said display panel and conformable to the peri-pheral surface thereof and defining with said first portion a chambered section yieldably accommodating movement of said safety plate relative to and in the direction of said display panel when said plate is subjected to a disturbing force; and mounting means for securing said E5 tube and said gasketed safety plate to said support member.

4. A television receiver comprising: a cathode-ray tube having a display panel; an escutcheon disposed in aparallel relation to said panel and having a configuration to effectively frame said panel; a transparent safety plate having an area at least substantially equal to the frame area provided by said escutcheon; means for yieldably suspending said safety plate between said escutcheon and said display panel and comprising an endless gasket having a first portion which defines a channel corresponding substantially to the outline of said safety plate for receiving and engaging said plate about its perimeter, said gasket having a second portion confronting said display panel and conformable to the peripheral surface thereof and defining with said first portion-a chambered section yieldably accommodating movement of said safety plate relative to and in the direction of said :display panel when said plate is subjected to a disturbing force; and mounting means embracing said tube for securing said tube to said escutcheon and for simultaneously fixing said tube, said escutcheon, and said gasket against relative movement.

5. A television receiver comprising: a cathode-ray tube having a display panel; an escutcheon disposed in -a parallel relation to said panel and having a configuration to effectively frame said panel; a transparent safety plate having an area at least substantially equal to the frame area provided by said escutcheon; means for yieldably suspending said safety plate in overlying relation to said display panel and within the aforesaid frame area comprising a gasket having a first portion which defines a channel corresponding substantially to the outline of said safety plate for receiving and engaging said plate about its perimeter, a second portion confronting said display panel and conformable to the peripheral surface thereof and defining with said first portion a principal chambered section yieldably accommodating movement of said safety plate relative to and in the direction of said display panel when said plate is subjected to an initial disturbing force, said gasket having a third portion confronting said escutcheon and conformable to the adjacent surface thereof and defining with said first portion a minor chambered section between said plate and said escutcheon and yieldably accommedating movement of said safety plate relative to and in the direction of said escutcheon when said plate is subjected to a second disturbing force; and means for normally fixing said tube, said escutcheon, and said gasket against relative movement.

6. A television receiver comprising: a cathode-ray tube having a display panel; a member disposed in a parallel relation to said panel and having a configuration to efiectively frame said panel; a transparent safety plate having an area at least substantially equal to the frame area provided by said member; pneumatically yieldable cushion ing means interposed between said display panel and said framing member and yieldably accommodating relative movement of said plate and said tube in a direction toward one another when said plate is subjected to a disturbing force; and means for normally fixing said tube, said framing member and said pneumatic cushioning means against relative movement.

7. A television receiver comprising: a cathode-ray tube having a display panel; a member disposed in a parallel relation to said panel and having a configuration to effectively frame said panel; a transparent safety plate having an area at least substantially equal to the frame area provided by said member; cushioning means for yieldably suspending said safety plate in overlying relation to said display panel and within the aforesaid frame area comprising a gasket having a channel for receiving and engaging said plate about its perimeter and a pneumatically yieldable portion confronting said display panel and yieldable to accommodate relative movement of said plate and said tube in a direction toward one another when said plate is subjected to a disturbing force; and means for 11' normally fixing said tube, said framing member and said gasket against relative movement.

8. A television receiver comprising: a cathode-ray tube having a display panel; a member disposed in a parallel relation to said panel and having a configuration to effectively frame said panel; a transparent safety plate having an area at least equal to the frame area provided by said member; cushioning mens for yieldably suspending said safety plate in overlying relation to said display panel and Within the aforesaid frame area comprising a gasket having a channel for receiving and engaging said plate about its perimeter, a first pneumatically yieldable portion confronting said display panel and yieldably accommodating movement of said safety plate relative to and in the direction of said display panel when said plate is subjected to an initial disturbing force, and a second pneumatically yieldable portion confronting said framing member and yieldably-accommodating movement of said safety plate relative to and in the direction of said member when said plate is subjectedto a second disturbing force; and means for normally fixing said tube, said framing member, and said gasket against relative movement.

References Cited in the file of this patent I UNITED STATES PATENTS Gethmann Dec. 14, 1948 2,497,660 Devine Feb. 14, 1950 2,559,353 Fisch July 3, 1951 2,870,438 Solheirn Jan. 20, 1959 2,936,448 Marholz May 10, 1960 FOREIGN PATENTS 938,73 Ge ia'n Feb. 9, 1956 214,649 A Australia Mar. 18, 1958 

6. A TELEVISION RECEIVER COMPRISING: A CATHODE-RAY TUBE HAVING A DISPLAY PANEL; A MEMBER DISPOSED IN A PARALLEL RELATION TO SAID PANEL AND HAVING A CONFIGURATION TO EFFECTIVELY FRAME SAID PANEL; A TRANSPARENT SAFETY PLATE HAVING AN AREA AT LEAST SUBSTANTIALLY EQUAL TO THE FRAME AREA PROVIDED BY SAID MEMBER; PNEUMATICALLY YIELDABLE CUSHIONING MEANS INTERPOSED BETWEEN SAID DISPLAY PANEL AND SAID FRAMING MEMBER AND YIELDABLY ACCOMMODATING RELATIVE MOVEMENT OF SAID PLATE AND SAID TUBE IN A DIRECTION TOWARD ONE ANOTHER WHEN SAID PLATE IS SUBJECTED TO A DISTURBING FORCE; AND MEANS FOR NORMALLY FIXING SAID TUBE, SAID FRAMING MEMBER AND SAID PNEUMATIC CUSHIONING MEANS AGAINST RELATIVE MOVEMENT. 